A hydroxyalkyl (meth)acrylate such as 2-hydroxyethyl (meth)acrylate and 2-hydroxypropyl (meth)acrylate is used as a monomer for producing a poly(meth)acrylate resin. Among general (meth)acrylate monomers, a hydroxyalkyl (meth)acrylate has a characteristic of having a hydroxy group; therefore, a poly(meth)acrylate resin produced using a hydroxyalkyl (meth)acrylate as one of raw material compounds has hydroxy groups on side chains.
The above-described hydroxy group has good reactivity, since the hydroxy group is bound to a main chain through an alkylene group. Therefore, the above-described poly(meth)acrylate resin having the hydroxy groups on side chains can be crosslinked, and other functional group can be introduced thereto.
For example, the above-described poly(meth)acrylate resin having the hydroxy groups on side chains can be used as a component of a high performance paint, since scratch resistance and acid resistance are improved by a modification such as crosslinking. In addition, since high adhesion property and high hydrophilicity are exhibited by the hydroxy groups, the resin can be used as a raw material for an adhesive and contact lens and also as a processing agent for a paper or a fabric which contain cellulose.
A hydroxyalkyl (meth)acrylate is generally produced by reacting (meth)acrylic acid with an alkylene oxide in the presence of a catalyst (Patent Document 1 or the like).
When a hydroxyalkyl (meth)acrylate is industrially produced, an impurity may be generated. Therefore, a technology to inhibit such an impurity has been developed. For example, Patent Document 2 discloses a method in which a reaction is carried out while an amount of (meth)acrylic acid relative to an amount of a catalyst is adjusted in order to inhibit the generation of a dialkylene glycol mono(meth)acrylate as an impurity.